Roasting apparatus



Sept- 13, J. L. KOPF ROASTING APPARATUS Filed July 24, 1959 um on 5 0N0N .TN H ow dd 4 ma .N Q 4 U m a I .5 X mm Q 3m H5015 5 m6 an INVENTOR.

JOSEPH L. KOPF,DECEASE|D BY ANNA R KOPF,EXECUTRIX ROASTING APPARATUSJoseph L. Kopf, deceased, late of East Orange, N.J., by

R. Kopf, executrix, East Orange, N.J., assignor to Jabez Burns & Sons,Inc., New York, N.Y., a corporation of New York Filed July 24, 1959 Ser.No. 829,375

2 Claims. (Cl. 263-32) This invention relates to an improved method andapparatus for roasting coffee, cocoa beans, peanuts, cereals and similarproducts and is an improvement over the disclosures of United StatesPatent No. 1,991,190 granted February 12, 1935, to L. H. Backer et al.

The main object is to burn up the smoke particles and foreign materialgiven off during the roasting and to eliminate odors so that thedischarge to the atmosphere is odorless, clean and invisible andcontains no elements or substances which would contaminate theatmosphere. This is of great importance as it overcomes the smoke andodor nuisance in the neighborhood of a roasting plant, thereby avoidingcomplaints and increasing the desirability and value of surroundingproperty. A further object is to accomplish this without the use of anyspecial auxiliary apparatus thus avoiding the extra cost thereof and thespace occupied thereby. Another object is to eliminate smoke particlesand foreign material from the heated gases which pass over and throughthe materials to be roasted. This improves the flavor, development andappearance of the final product. A further object is to shorten the timerequired in the roasting operation. Other objects are to avoid the riskof scorching or spotting of the roast and to reduce the cost ofroasting. Other objects and advantages will be understood from thefollowing description and accompanying drawing showing a preferredembodiment of the invention.

The drawing is a side view of the apparatus, partly in section, anddiscloses the means whereby the method may be performed.

The said prior Patent 1,991,190 discloses and explains the advantagesthereof over prior methods, and such advantages are attained by thepresent invention with additional advantages above referred to.

Referring to the accompanying drawing, a roaster casing 1 encloses theroasting chamber. A rotatable perforated cylinder or carrier 2 driven bya motor (not shown) serves to contain the material to be roasted. Aplurality of mixing vanes 3 secured within the cylinder 2 serves to mixthe material and carry it from the lower portion of the cylinder to thetop portion and to constantly agitate it during roasting. Within thecentral portion of the cylinder and supported by the rear head of thecasing 1 is an elongated peaked hood or spreader 4, the peak beinguppermost. The vanes 3 lift the material and drop it on the hood whichserves to spread the material.

A swing gate 5 is pivoted at 6 to the front head of the casing. Whenthis gate is swung forward, as shown in the drawing, it covers thedischarge chute 7 and permits raw material to be fed from the hopper 8through the feed pipe 9 into the cylinder 2, the flow of material beingcontrolled by the slidable feed gate 10. When the gate 5 is swungbackwardly to the position shown in dotted lines, it acts as an outletfor passing the material through the discharge chute 7 into the coolerbox 12 for cooling as later described.

The heating and smoke consumer may be a flame, or an Patented Sept. 13,1960 ice incandescent body which may be heated electrically, or may be ahighly heated atmosphere supplied by any suitable means. In the presentinstance a flame is utilized, being produced in this instance by a motordriven blower 13 arranged to premix gas with a proper volume of air fors most eflicient combustion and discharge the mixture through a nozzle14 disposed in the combustion chamber formed by the casing 15. Thecasing 15 is shown as having an inner liner 16 of fire clay or otherrefractory or heat resisting material, and is connected to the rear endof the cylinder 2 beneath the hood 4. Opposite the nozzle 14 are vanes11 extending outwardly and at an angle for diffusing the flamethroughout the chamber for insuring complete combustion of the smoke andother particles. The vanes or blades of this spreader are supported infixed position from the end of the nozzle by rods 11a. A thermocouple 17is mounted beneath the hood 4 near the combustion chamber and isconnected to a dial 18 for the purpose of indicating the temperature ofthe heating medium as it enters the roasting cylinder.

An exhaust fan 19 is connected to the lower portion of the roastingcasing by a suction pipe 20. A branch suction pipe 21 having a damper 22is connected to the feed pipe 9. The outlet pipe 23 from the fan 19 isconnected to a separator 24 of any suitable type for removing chatf andlight trash, which fall into a receptacle 25. The top of theseparator'opens into a discharge or bleeder pipe 26 which leads to theatmosphere, and to a return pipe 27 which is connected to the combustionchamber adjacent the burner nozzle.

The cooler box 12 is shown as having a hood 28 and a pipe 29 connectedto a suction fan 30 which draws air upward through the, perforatedbottom wall 31 of the cooler. The material after cooling is dischargedfrom the cooler through a door 32.

The foregoing description corresponds generally to the disclosures ofthe apparatus in said prior Patent No. 1,991,190. The presentimprovements in the method and apparatus will appear from the following.

A further bleeder outlet or conduit is provided by pipe 33 connectedfrom the end portion or exit of the combustion casing, which is near theroasting chamber, to the bleeder pipe 26 and to the pipe portion 34which leads from the recirculating pipe connections to atmosphere. Adamper 35 is located in the pipe portion 34 between the outlets to pipes27 and 33. Another damper 36 is provided in the, pipe connection 33 andanother damper 37, shown slidable, is located at the end of thecombustion casing between the pipe connection 33 and the roastingcasing.

In the prior Patent 1,991,190 a special auxiliary smoke burner isdisclosed located in the bleeder pipe for reduc' ing the smoke nuisancein the atmosphere. This involves extra cost and space occupied, and sucha burner to be at all effective and durable would have to be lined withrefractory material. The present improved method of control andapparatus avoids the need of any auxiliary device by consuming the smokeand foreign particles in the combustion chamber of the roaster, whichthus serves not only to provide the heating for the roast but also toeliminate the smoke and odors from the discharge to atmosphere and alsofrom the heated-gases passing to the roasting chamber. Not only is thesmoke nuisance abated, but the character of the roast is greatlyimproved in quality, flavor and appearance because the smoke and othercombustible particles are more effectively eliminated from the roastingchamber.

The three dampers 35, 36 and 37 are operated in proper relation forobtaining the most advantageous method of control. In such operation atthebeginning of the roast, the damper 36 in the passage 33 is closed andthe dampers 35 and 37 are open. The heated gases then pass from hecombustion chamber through the material in the roasting chamber, thenthrough the separator and through the connection 27 to the combustionchamber and so on in he recirculating system. The excess gasespassthrough the open damper 35 to bleed ofl to the atmosphere. Duringthis condition of operation, no smoke or vapors from the roast areformed as the heating up of the roast continues to the proper roastingtemperature. A considerable saving in heat units is thereby obtainedbecause nearly all of the heat is then absorbed into the roast. Thispreheating in this step of the method usually takes about four minutesfor a normal load of coflee beans and with a proper temperature of theheating gases.

When smoke and vapors begin to be given oil. from .-the roast, thedamper 36 is opened and the damper 35 is closed, the damper 37 remainingopen. The heated gases from the combustion chamber then pass through thematerial, then through the separator and, as the damper 35 is closed,the recirculation is continued through the connection 27 to thecombustion chamber. The stream returned to the combustion chambercontains smoke particles, vapors, odors and various other particles notremoved by the separator but which are consumed in the combustionchamber as the source of heat in this chamber is maintained suflicientlyhigh to burn up all such particles. A minor portion of the stream passesout through the connection 33 to the bleeder pipe 26 free from smoke andodors in a clear, clean and non-visible stream and thus does notcontaminate the atmosphere. The major portion of the stream passes tothe roasting chamber in its recirculating path and as this portion iscleaned of smoke and other combustible particles, it improves the flavorand appearance of the roast over less eflicient cleaning of the hotgases. This method of control thus avoids any auxiliary smokeeliminating device and is highly eflective in purifying the gas streamto the roast and to the atmosphere.

The deflector means are positioned in the path of the flame emanatingfrom the burner nozzle and by so directing and diflusing the flame in anoutwardly direction against the walls of the combustion chamber therecirculated gases are assured of coming in contact with the flame so asto be burned up. The recirculated gases which are introduced into thecombustion chamber might have a tendency to follow and adhere to thewalls of the combustion chamber and, if such were the case, the flamewould not in all probability engage and contact said gases it deflectormeans were not associated with the flame in such a manner as to bring itagainst the walls of the combustion chamber. The recirculated vapors andgases will be sure to contact said flame, even though said gases andvapors might tend to flow along the walls of the combustion chamber.

The end point at which the proper roasting of coflee, for example, iscompleted, is quite critical and when reached should be stopped quickly.This is commonly accomplished by extinguishing the fuel supply, checkingthe roast with a spray of water and discharging the roasted materialinto the cooler box, the fumes and vapors being passed to theatmosphere. This serves to contaminate the atmosphere. By the presentimprovement, the fuel supply is not shut off, the damper 37 is closed,the damper 36 remains open and the damper 35 remains closed. The roastis then sprayed with water within the roasting chamber for quicklychecking the roasting. The smoke, odors and vapors are then drawn by theexhaust fan 19 and passed through the cleaner and then through theconnection 27 to the combustion chamber. Here all the smoke andcombustible particles are consumed and the water and other vapors areheated to a high temperature. All the stream is then passed through theconnection 33 and out through the bleeder pipe to atmosphere. Thisdischarge to atmosphere is smokeless and odorless. It is also invisiblebecause the vapors, especially the water vapor, are at such a hightemperature that they do not condense to a visible mist. By this methodnot only is the roast quickly cooled at the critical time, but thedischarge to the atmosphere is in no way objectionable. After sufficientquenching and cooling, the roasted material is discharged to the coolerbox for further cooling.

The roastingchamber may then be reloaded and the foregoing describedmethod or cycle of operations repeated.

Although more heat units are required in the combustion chamber to burnup the smoke and other particles 7 and also to roast the material thanto merely roast the material, this improvement is more eflicient andeconomical than prior methods and the total time for roasting isshortened due considerably to the rapid heating up step in starting theroast. This shortened time of roasting, of course, increases thecapacity of a roasting plant.

In some cases the separator may be omitted from the recirculatingsystem. Likewise the cooler box may not be required. Also the first stepof heating up the roast in the manner described may not be employed,although it is highly advantageous. Also the method of quenching theroast in the combustion chamber for quickly terminating the roastingperiod and for burning up the combustible matter with a clean and cleardischarge to the atmosphere may not always be utilized, although it ishighly preferable.

Although a preferred method and general form of apparatus have beendescribed, various modifications may be made without departing from thescope of the,

invention.

This application is a continuation-in-part of copending applicationSerial No. 180,175, filed August 18, 1950, now abandoned, for RoastingApparatus.

What is claimed is:

1. A cofiee roaster for coffee beans and the like comprising a roastingdrum, a preceding smoke-consuming combustion chamber burning combustibleparticles and passing heated gases to said roasting drum, recirculatingmeans passing gases, smoke, vapors and the like from said roating drumand delivering them to said combustion chamber, nozzle means introducinga mixture of fuel and air to produce a flame in said combustion chamber,means diffusing and intermixing the recirculated smokeladen vapors andgases in said flame to completely burn up smoke particles and foreignmaterial in the recirculated gases, smoke and the like as they passthrough said chamber, a bleeder pipe connected to said recirculatingmeans between said drum and said combustion chamber for exhausting gasesto atmosphere and having an adjustable valve to vary and shut off thegases passed through said bleeder pipe, a bleeder conduit opening fromsaid combustion chamber for passing gases to atmosphere while continuingthe flow through said recirculating means and combustion chamber forregulating the amount of gases passed to atmosphere and having a by-passvalve in cooperation with the adjustable valve of the bleeder pipe.

2. A coffee roaster for coffee beans and the like as set forth in claim1 in which an adjustable damper means is positioned to move in the flowof the heated gases from the combustion chamber to the roasting drum andacting to vary the outflow of said gases from said chamber to said drumand cooperate with said bleeder conduit in control of the relativeproportion of the flow through said combustion chamber going to saidroasting drum.

Hopkins et al Jan. 19, 1932 Backer et a1 Feb. 12, 1935

